The theme-song for the 1967 Spider-Man TV show has this part:

Is he strong?
Listen bud,
He's got radioactive blood.

I assume that "radioactive" in this case means that it is currently producing radiation.

While the spider that bit Peter Parker was certainly radioactive, did it make Peter's blood radioactive? And is it still radioactive years after the spider bite?

I'm looking for an answer that addresses the main comics universe (Earth-616) and/or the 1967 television show. Other universes are welcome as supplementary material.

  • 14
    "Spider-Man kills Mary Jane with radioactive sperm"
    – Valorum
    Commented Jun 12, 2018 at 22:42
  • 6
    In Amazing Spider-Man Vol 1 #10 he transfused his blood into Aunt May. In issues #31-33 she's quite poorly (as a result) but the blood ultimately heals her.
    – Valorum
    Commented Jun 12, 2018 at 22:48
  • 3
    Isn't everyone's blood radioactive? I guess your asking if Spiderman's blood is more radioactive than usual?
    – user14111
    Commented Jun 13, 2018 at 3:04
  • @user14111 Well, it's presented as a compelling argument to explain why Spider-Man is strong. So yes, more radioactive than normal humans to explain why he is stronger than normal humans. Commented Jun 13, 2018 at 3:13
  • 15
    @Thunderforge - Are you suggesting that the theme tune may be in some way innaccurate?! (Monocle drops into champage). Maybe we should also ask if he can spin a web of any size.
    – Valorum
    Commented Jun 13, 2018 at 6:24

5 Answers 5


Yes, it is. Spoilers following.

Morlun is a "recent" foe of Spider-Man, appeared for the first time in The Amazing Spider-Man Vol. 2 #30 (2001).

Long story short, he wants to feed on Spider-Man's blood and he is way stronger than Spider-Man, so our hero needs to find a way to win the fight.

With a test he discovers that Morlun is vulnerable to radiation and thus, in The Amazing Spider-Man Vol. 2 #35, Spider-Man injects himself with a nice dose of radiation because even if it could kill a normal man, it will only weaken him due to the high dose of radioactivity already present normally in his own blood.

relevant The Amazing Spider-Man Vol. 2 #35 panel relevant The Amazing Spider-Man Vol. 2 #35 panel relevant The Amazing Spider-Man Vol. 2 #35 panel

Going back in time, in Amazing Spider-Man Vol. 1 #32 Spider-Man discovers that Aunt May is dying because of radioactive material in her blood, due to blood she received from him during a transfusion.

So yes, right now Spidey's blood is sensibly more radioactive than normal blood.

  • 4
    Some panels to confirm these facts would be appreciated.
    – Valorum
    Commented Jun 13, 2018 at 19:46
  • 4
    @Valorum: no problem, it's just 270 euro the ticket to fly to my storage to grab the comics, what is the address to send the bill to? :-D But there are some additional info in different wikis, I'll link and quote them too.
    – motoDrizzt
    Commented Jun 13, 2018 at 19:53
  • I'm just looking at ASM Vol 2. #35. Although he injects himself with radioactive material, there's no good indication that it lasts in his system for very long.
    – Valorum
    Commented Jun 13, 2018 at 20:32
  • 3
    The 1967 theme song is, to me, always the deciding canon on all issues of a Spidey nature
    – Danny Mc G
    Commented Jun 14, 2018 at 12:07
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    Not to mention, the radioactive sperm. Commented Sep 11, 2018 at 11:40

I'd say yes because it becomes the center of the lyrics to the opening of Spider-Man: The Animated Series:

Spider-Man, Spider-Man

Radioactive Spider-Man

Spider blood, spider blood,

Radioactive spider blood


It doesn't come up often, but a few scenes over the years have reiterated that the Earth-616 version of Spider-Man does indeed have radioactive blood.

PETER PARKER: Radioactivity in her blood stream?!! It must be my fault! I'm the one responsible! It must have happened that time she needed a blood transfusion--and I donated my blood! Some of the very radioactivity which transformed me to Spider-Man must have gotten into her blood stream! Only, in her case, it's proving harmful!

Amazing Spider-Man Vol. 1 #32, page 4.

Amazing Spider-Man Vol. 1 #32 (January, 1966)

RADIOACTIVE MAN: You're an interesting specimen, Spider-Man. My preliminary tests show that the radiation I sense originates in your blood.

Iron Man Vol. 1 #234, page 17.

Iron Man Vol. 1 #234 (September, 1988)

BLADE: Spider-Man's got radioactive blood. Us Weekly did a piece.

Blade Vol. 4 #1, page 9.

Blade Vol. 4 #1 (November, 2006)

In fact, it's been indicated to be a necessary component of his powers, such that if you were to cleanse his blood of radiation, he would weaken or lose his powers altogether.

SPIDER-MAN: My blood! Radioactive spider-blood! He's cleansing it! No! That's where my powers come from!

Amazing Spider-Man Vol. 1 #571, page 2.

Amazing Spider-Man Vol. 1 #571 (November, 2008)

  • "US Weekly did a piece" Commented Aug 19, 2021 at 16:41

The original Spider Man powers came from a radioactive spider bite, as seen in Amazing Fantasy 15

One evening, while attending a demonstration of radioactivity at General Techtronics Laboratories East, Parker fails to notice a spider drop through a "radioactive ray" and receive a massive dose of radiation. It bites him and dies. Light-headed, Parker leaves the demonstration, only to be nearly run over by a car. He leaps to safety but is surprised to find he has jumped much further than intended—he lands on the side of a building and clings to the bricks by his fingertips. He quickly climbs to the roof and, once there, accidentally crumples a steel pipe in his hand. He believes that he has inherited the spider's speed, strength, and climbing ability. He begins to ponder the possibilities.

Now, if he had truly "radioactive blood" he wouldn't be much of a superhero ("Hey, I saved you from that supervillan but dosed you with enough radiation to possibly give you cancer. You're welcome!") But, in one of Marvel's stranger decisions, the series Spider Man: Reign has this

It is revealed that [Mary Jane] died of cancer brought on by exposure to Peter's radioactive bodily fluids during intercourse over the years.

So no radioactive blood, but radioactive semen...

  • 1
    Which, to be fair, is set in a future timeline on a divergent Earth, so this could only show that SOME Spiders-Man have dangerously radioactive fluids. The Earth where they have May, who becomes Spider-Girl, the...exposure was far from fatal. Commented Jun 13, 2018 at 14:02
  • Alpha particles can be absorbed by skin, so if he is emitting that type of radiation, not only would it be difficult for other people to be exposed, but it wouldn't be very dangerous. Alpha particles are generally dangerous only when they're being emitted from an internal source. Commented Jun 13, 2018 at 15:14
  • 3
    "Is he strong? Listen stooge, He has radioactive spooge! Look out, here comes the Spider Mannnnnnn"
    – Irishpanda
    Commented Jun 13, 2018 at 18:16
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    @Irishpanda I think that might be the Spooderman theme
    – Machavity
    Commented Jun 13, 2018 at 18:21

Theme songs have the job of delivering a great deal of info in about a minute, and as such have to pack in a lot, and if at all possible, make the song rhyme.

So "radioactive blood" is extreme shorthand for introducing the idea that radiation was obliquely connected to his origin and powers. And it rhymes with "bud". Otherwise you'd have been stuck with lines like...

From society he's an outsider

He's got the proportional strength of a spider!

For the record, he doesn't swing from "thread" either. And The Hulk has much more strength than "the power of a bull".

  • 4
    So... Is Spider-Man's blood really radioactive or not?
    – TheLethalCarrot
    Commented Jun 13, 2018 at 13:16
  • Well, John Byrne didn't think so... byrnerobotics.com/forum/forum_posts.asp?TID=41659 Commented Jun 13, 2018 at 13:20
  • 1
    @VBartilucci That quote from John Byrne seems to address the question pretty well. It explains that radiation altered it, but it's not emitting radiation so you couldn't, for instance, use a geiger counter to help find him. Could you perhaps incorporate that into the answer? Commented Jun 13, 2018 at 14:29

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